反应详情

温度

5 °C

1. 66.2 g of 2-amino-6-methylbenzonitrile and 22 g of acetonitrile are dissolved in 750 ml of absolute dioxan and the solution is cooled to 5° C. Subsequently, a weak stream of dry hydrogen chloride is introduced for 8 h. at 5° to 7° C. The mixture is stirred at room temperature for a further 15 h. and then again cooled to 5° C. A further 11 g of acetonitrile are added thereto, hydrochloric acid gas is introduced for 8 h. and the mixture is stirred at room temperature for a further 15 h. The suspension is subsequently evaporated at 30° C. in a vacuum. The crystalline residue is triturated with 0.71 of water, cooled to 0° to 5° C. neutralized with saturated sodium hydrogen carbonate solution and filtered. The crystals are washed with water and dried in a vacuum. There are obtained 107 g of crude 4-amino-2,5-dimethylquinazoline which still contains inorganic salts. This compound melts at 198°-199° C. after recrystallization from ethanol.

1. temperatureagain cooled to 5° C
2. stirringthe mixture is stirred at room temperature for a further 15 h
3. customThe suspension is subsequently evaporated at 30° C. in a vacuum
4. customThe crystalline residue is triturated with 0.71 of water
5. temperaturecooled to 0° to 5° C.
6. filtrationfiltered
7. washThe crystals are washed with water
8. customdried in a vacuum